Identification of 19-norprogesterone in pregnant rat urine

The existence of biosynthetic pathways leading to the formation of 19-nor-androgens and corticoids have been established in animals and humans. The exact biologic function of the products of these pathways in vivo has yet to be established; however, it has been shown that they possess pronounced biologic activity when administered exogenously. This report describes the identification of 19-nor-progesterone isolated from the urine of pregnant rats. The procedures used included isolation as the underivatized material and methoxime derivative by thin-layer and high-performance chromatography. The identity was further confirmed by gas chromatography/mass spectral analysis of the isolated product as the 3,20-bis-methoxime derivative. The spectra obtained from the urinary product and the authentic 19-norprogesterone-3,20-bis-methoxime were identical. A possible biologic role for 19-norprogesterone or its precursors is discussed.